As part of a grant for pedagogical renewal awarded by TUFF at Uppsala University, we have developed a number of exercises that will teach the students about the night sky, using augmented-reality observations with free astronomy apps for Android and Iphone. In these exercises, the students will learn how to find the North star, identify stars and planets in the sky, learn more about solar eclipses, spherical coordinates and the difference between astronomy and astrology. These exercises have now been used in this year's edition of the course Introduction to Astronomy and are just about to be introduced in the third-year course Astrophysics I. So far, the feedback has been great! The students seem to enjoy these exercises and the technical problems have been remarkably few.

The first paper describing the simulations used within the LYCAN project was recently submitted and is publicly available as a preprint. In this paper, we explain how observations with the upcoming James Webb Space Telescope (launch in late 2018) will allow the identification of galaxies that leak large amounts of ionizing photons into the intergalactic medium at redshifts z>6. This is important for scenarios where galaxies provide the ionizing photons that caused the reionization of the Universe - the cosmic phase transition that took place at slightly less than one billion years after the Big Bang.

The first Gaia data release is out, and astronomers across the globe are busy studying the catalogs to learn more about topics as diverse as stars, exoplanets and dark matter. I myself have gotten interested in the potential of using Gaia to search for Dyson spheres. A super-brief outline of the idea is available here. The proposed method can be applied to some 200,000 objects from the Gaia data release, and MSc student Ansgar Wehrhahn has agreed to work on this throughout the fall.

Today, Beatriz Villarroel got a chance to talk on national television about her latest SETI paper, which describes a novel method to hunt for alien technosignatures using multiple-epoch survey data (see the Project hephaistos page for more details).

Martin Sahlén has received research funding for two years from Stiftelsen Olle Engkvist Byggmästare to join our group. Congratulations, Martin!

In a paper led by Akio Inoue (also featuring Erik Zackrisson) and published in the journal Science, we present some game-changing ALMA observations of an early-Universe galaxy at a redshift of z=7.2. This constitutes the most distant detection of the element oxygen so far, and confirms previous simulation predictions that the [OIII] emission line at a rest-frame wavelength of 88 micron may be the best way to hunt down galaxies at very high redshifts with ALMA. An analysis of all the spectral information available for the target galaxy moreover indicates that it may be leaking copious amounts of ionizing radiation into the intergalactic medium, with important implications for the reionization of the Universe.

Our first paper on machine learning in the study of first galaxy spectra has been submitted to the Astrophysical Journal and is now available as a preprint.

A couple of weeks ago, we posted our paper on the cosmological distribution of terrestrial planets on the arXiv preprint server. It got some fair coverage on Astrobites and by Scientific American, but then something curious happended... As more bloggers and journalists got interested, the claimed content of the paper got increasingly distorted, until headlines like "Earth is different from 700 quintillion planets in the Universe" and "Latest Research Says that the Earth Shouldn't Exist" started appearing. And based on the emails I've been getting lately, I strongly suspect that someone out there is trying to put a religious spin on all of this. Internet - you gotta love it...

Today, Saghar successfully defended her Licentiate thesis "Gravitational lensing and radio interferometry as a probe of the small–scale structure of dark matter" at Stockholm University. Congratulations, Saghar!

Good news for Swedish SETI! Not only did Project Hephaistos recently get some research funding from Nordenskjöldska Swedenborgsfonden, but we were also awarded observing time for SETI follow-up observations using the APEX telescope. Merry X-mas!

As an exercise in making concrete representations of abstract scientific concepts, we asked the students in the cosmology course to explain the four hierarchies of parallel universes defined by Max Tegmark, using lego. This turned out to be both fun and educational. Here's an example of how an encounter with an armed stormtrooper branches off into three different Everett worlds (level III parallel universes) with different, colour-coded probabilities.

Most galaxies in the local Universe are old - several billion years at least. This image, which has been constructed from Very Large Telescope data that I obtained a few years ago, captures a number of genuinely young galaxies that have formed in the tidal debris left over from the collision of two larger galaxies. This image now features in a fancy image/video release by ESO, in connection to a paper in which my old FORS data is combined with spectroscopy from the new Very Large Telescope instrument MUSE to reveal a number of puzzling features in the spectra of these objects.

We now have a new PhD student in our group - Christian Binggeli. Christian will be working on high-redshift galaxies and their role in the reionization of the Universe. Welcome, Christian!

This week, I attended a James Webb Space Telescope (JWST) meeting at the European Space Agency centre ESTEC in the Netherlands and gave a talk on the role of JWST in studying the role of galaxies in the reionization of the Universe (here's a link to the talk). After a couple of days, I rushed off to the Square Kilometer Array (SKA) epoch-of-reionization key science project meeting in Groningen to discuss how to coordinate SKA with other telescopes to make the most of the surveys planned for the SKA low-frequency array in Australia. Busy week, but pretty exciting!

This semester, me and Hannes Jensen (new postdoc in our group) are involved in a cross-disciplinary project together with Kristiaan Pelckmans, Rubén Cubo, Ulrika Lundholm and Kristiina Ausmees from the Department of Information Technology. The idea is to develop machine learning techniques to study galaxies in the early Universe, and more specifically to extract information about the escape of ionizing radiation from high-redshift (z>6) galaxies observed with the upcoming James Webb Space Telescope (JWST). In a paper of ours from a couple of years ago (Zackrisson et al. 2013), we proposed that this information should be retrievable from JWST spectra, but did not go to great lengths to figure out just how far this method could be pushed. With the help of this crew, we should be able to find out!

Over the last three days, astronomers from across the globe have gathered at the Wennergren centre in Stockholm to discuss key science projects for the upcoming Square Kilometer Array (SKA), a huge radio telescope to be constructed in 2020-2023 in South Africa and Australia. Since the SKA will be a game changer in the study of the reionization of the Universe and the emergence of the first stars and galaxies, I'm of course very eager to get onboard. Several astronomers (including yours truly) were interviewed by national television during this meeting, but the only snippets that actually aired were about - you guessed it - aliens. Yes, with the SKA, you could indeed eavesdrop on radio signals from nearby civilizations, but this is not the reason why the SKA is built - it's more or less just a side effect of constructing a radio telescope of this scale. Even though I'm all in favour of SETI (Searching for Extraterrestrial Intelligence), I have to confess that I feel pretty ambivalent about SETI getting all the limelight on this particular occasion. The SKA is primarily built to shed new light on the formation of planets and complex molecules in space, on cosmic magnetism and the early Universe, on putting theories of gravity to the test and to learn more about the large-scale structure of the Universe. Given the monumental cost of a telescope like this, perhaps it's a good idea to let the tax payers know that we're not just building a giant ear to gauge how deep the eerie silence goes? The problem, of course, is that it's so much easier for journalists to spin a tale about leakage from alien radar stations than to make the state of the intergalactic medium sound sexy. What would the best media strategy at a meeting like this be? To simply refuse to answer questions on SETI? Not sure, but this deserves some pondering, since this is a problem that is going to resurface again and again.

The first paper from our SETI project is now in print in Astrophysical Journal. We've also launched the Project hephaistos homepage. Be sure to check out Saghar Asadi's galactic colonization simulations - they're supercool.

Lots of changes in the gang lately... Claes-Erik Rydberg has taken up a postdoc in Heidelberg, where he will continue his work on the first stars and galaxies in the group of Ralf Klessen. We wish Claes-Erik the best of luck (but secretly hope that he will return to us one day). Per Calissendorff recently presented his MSc thesis Planets throughout space and time (see picture below) and is now off to the Canary Islands to work at the Swedish Solar Telescope. On top of that, Hannes Jensen, a PhD student that I've been co-supervising at Stockholm University, defended his PhD thesis Simulating observational probes of reionization. However, if all goes well, both Per and Hannes will be joining us in Uppsala in the fall - Per to work on SETI and Hannes to work on machine learning algorithms for the analysis of James Webb Space Telescope spectra.

We now have an opening for a PhD student eager to explore the mysteries of the high-redshift Universe. The application deadline is May 31, 2015. Please use this link if you're interested in applying!

This week, I attended the South by High Redshift conference in Austin and gave a talk on our paper about Population III galaxies at extreme magnifications. Lots of cool stuff was presented at this meeting, but the talk that really blew my mind was the one by David Sobral on a new Population III galaxy candidate at redshift z = 6.6. This could be a game-changer! The slides from the talks can be downloaded from the conference homepage.

Our paper on extreme forms of gravitational lensing has just been accepted by the Monthly Notices of the Royal Astronomical Society. Gravitational lensing allows you to observe objects in the distant Universe that are otherwise too faint to be detected with telescopes. These days, lensed galaxies are routinely detected with magnification factors of ten to a hundred, but not with magnifications much higher than this. Why not? Basically because the probability for this is too low and because galaxies are too big. Magnification factors of thousands are by no means impossible, but this requires light sources that are fairly compact (just a few parsecs across). You also need a source population with a high number density (many sources per square degree in the sky), and a survey with a very large areal coverage to find them. In this paper, we use gravitational lensing simulations to quantify the probabilities for extreme magnifications in the distant Universe. We also investigate what sort of light sources and surveys this may be relevant for. As it turns out, extreme magnification factors may allow the Ultra Deep Survey considered for the Japanese WISH telescope to detect primordial star clusters (with zero-metallicity stars, so-called Population III stars) at redshifts z = 7 to 13. Pretty cool! A preprint of the paper is available here.

This semester, the Galaxies and Cosmology group is hosting three MSc students: Per Calissendorff (left), Kostas Liolios (middle) and Christian Binggeli (right). Per is modelling exoplanet formation in a cosmological perspective, Kostas is analyzing Keck observations of galaxies at redshift z=3 and Christian is simulating the spectra of galaxies in the reionization epoch. We're also hosting one BSc student - Marika Ljungberg (not in picture), working on black hole signatures in high-redshift galaxies.

The local radio station P4 Uppland did a short piece on our search for extraterrestrial intelligence. The live interview is availble here. Also, Florent Duval, a PhD student that I've been co-supervising at Stockholm University, successfully defended his thesis. Congratulations Dr. Duval!

Beatriz Villarroel gave a talk at the Transient Universe for All meeting in Lund. You can find the meeting webpage here.

AGN aficionados Andreas Korn and Beatriz Villarroel have published a paper in the February issue of Forskning och Framsteg, Sweden's foremost popular science magazine. Read all about it on Beatriz' new homepage!

Today, my student Claes-Erik (Utte) Rydberg successfully defended his PhD thesis "Gravitational lensing as a probe of the first stars and galaxies" at Stockholm University. A link to his thesis is available here.

Nils Bergvall's monumental paper on starburst galaxies is the Sloan Digital Sky Survey has been brewing for a long time, but has now finally been submitted. Conrats! Local co-authors include Thomas Marquart, Michael Way, Anna Blomqvist, Emma Holst and myself. A preprint of the paper is available here.

We've received a small research grant for our SETI (Searching for Extraterrestrial Intelligence) projects. As far as I know, this is the first SETI grant ever awarded in Sweden. Major kudos to the Magnus Bergvall Foundation! The funding will likely be used to pay the salary of a summer student to work on SETI. If this had happended when I was an undergrad, I would've killed for that job!

My student Claes-Erik Rydberg has just gotten his PhD thesis "Gravitational lensing as a probe of the first stars and galaxies" back from the printer. The thesis defence will take place in Stockholm on January 30.